• IMMUNE NETWORK
• /
• v.3 no.2
• /
• pp.110-117
• /
• 2003

Background: The usefulness of DNA vaccine at priming step of heterologous prime-boost vaccination led to DNA vaccine closer to practical reality. DNA vaccine priming followed by recombinant viral vector boosting via systemic route induces optimal systemic immunity but no mucosal immunity. Mucosal vaccination of the reversed protocol (recombinant viral vector priming-DNA vaccine boosting), however, can induce both maximal mucosal and systemic immunity. Here, we tried to address the reason why the mucosal protocol of prime-boost vaccination differs from that of systemic vaccination. Methods: To address the importance of primary immunity induced at priming step, mice were primed with different doses of DNA vaccine or coadministration of DNA vaccine plus mucosal adjuvant, and immunity including serum IgG and mucosal IgA was then determined following boosting with recombinant viral vector. Next, to assess influence of humoral pre-existing immunity on boosting $CD8^+$ T cell-mediated immunity, $CD8^+$ T cell-mediated immunity in B cell-deficient (${\mu}K/O$) mice immunized with prime-boost regimens was evaluated by CTL assay and $IFN-{\gamma}$-producing cells. Results: Immunity primed with recombinant viral vector was effectively boosted with DNA vaccine even 60 days later. In particular, animals primed by increasing doses of DNA vaccine or incorporating an adjuvant at priming step and boosted by recombinant viral vector elicited comparable responses to recombinant viral vector primed-DNA vaccine boosted group. Humoral pre-existing immunity was also unlikely to interfere the boosting effect of $CD8^+$ T cell-mediated immunity by recombinant viral vector. Conclusion: This report provides the important point that optimally primed responses should be considered in mucosal immunization of heterologous prime-boost regimens for inducing the effective boosting at both mucosal and systemic sites.

• Journal of Microbiology
• /
• v.45 no.2
• /
• pp.179-184
• /
• 2007

Pasteurella multocida, a Gram-negative facultative anaerobic bacterium, is a causative animal pathogen in porcine atrophic rhinitis and avian fowl cholera. For the development of recombinant subunit vaccine against P. multocida, we cloned and analyzed the gene for outer membrane protein H (ompH) from a native strain of Pasteurella multocida in Korea. The OmpH had significant similarity in both primary and secondary structure with those of other serotypes. The full-length, and three short fragments of ompH were expressed in E. coli and the recombinant OmpH proteins were purified, respectively. The recombinant OmpH proteins were antigenic and detectable with antisera produced by either immunization of commercial vaccine for respiratory disease or formalin-killed cell. Antibodies raised against the full-length OmpH provided strong protection against P. multocida, however, three short fragments of recombinant OmpHs, respectively, showed slightly lower protection in mice challenge. The recombinant OmpH might be a useful vaccine candidate antigen for P. multocida.

• Journal of Life Science
• /
• v.11 no.4
• /
• pp.385-391
• /
• 2001

Filamentous hemagglutinin (FHA) is considered as an essential immunogenic component for incorporation into acellular vaccines against Bordetella pertussis, the causative agent of whooping cough. Classically, antipertussis vaccination has employed an intramuscular route. An alternative approach to stimulate mucosal and systemic immune responses is oral immunization with recombinant live vaccine carrier strains of Salmonella typhimurium. An attenuated live Salmonella vaccine sgrain($\Delta$cya $\Delta$crp) expressing recombinant FHA(rFHA) was developed. Stable expressionof rFHA was achieved by the use of balanced-lethal vector-host system. which employs an asd deletion in the host chromosome to impose in obligate requirement for diaminopimelic acid. The chromosomal $\Delta$asd mutation was complemented by a plasmid vector possessing the asd$^{+}$ gene. A 3 kb DNA fragment encoding immuno dominant regionof FHA was subcloned in-frame downstream to the ATG translation initiation codon in the multicopy Asd$^{+}$ pYA3341 vector to create pYA3457. Salmonella vaccine harboring pYA3457 expressed approximately 105kDa rFHA protein. The 100% maintenance of [YA3457 in vaccine strain was confirmed by stability examinations. Additionally, a recombinant plasmid pYA3458 was constructed to overpress His(8X)-tagged rFHA in Essherichia coli. His-tagged rFHA was purified from the E. coli strain harboring pYA3458 using Ni$^{2+}$-NTA affinity purification system.>$^{2+}$-NTA affinity purification system.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.11
• /
• pp.1960-1965
• /
• 2015

Rabbit hemorrhagic disease virus (RHDV) is highly contagious and often causes fatal disease that affects both wild and domestic rabbits of the species Oryctolagus cuniculus. A highly pathogenic RHDV variant (RHDVa) has been circulation in the Korean rabbit population since 2007 and has a devastating effect on the rabbit industry in Korea. A highly pathogenic RHDVa was isolated from naturally infected rabbits, and the gene encoding the VP60 protein was cloned into a baculovirus transfer vector and expressed in insect cells. The hemagglutination titer of the Sf-9 cell lysate infected with recombinant VP60 baculovirus was 131,072 units/50 μl and of the supernatant 4,096 units/50 μl. Guinea pigs immunized twice intramuscularly with a trial inactivated RHDVa vaccine containing recombinant VP60 contained 2,152 hemagglutination inhibition (HI) geometric mean titers. The 8-week-old white rabbits inoculated with one vaccine dose were challenged with a lethal RHDVa 21 days later and showed 100% survival rates. The recombinant VP60 protein expressed in a baculovirus system induced high HI titers in guinea pigs and rendered complete protection, which led to the development of a novel inactivated RHDVa vaccine.

• BMB Reports
• /
• v.31 no.5
• /
• pp.432-443
• /
• 1998

The poliovirus Sabin 1 strain has features that make it a particularly attractive live recombinant mucosal vaccine vehicle. Sabin 1 cDNA was manipulated to have multiple cloning sites and a viral specific 3C-protease cutting site at the N-terminal end of the polyprotein. The gene for the N-terminal 169 amino acids of the HIV-1 p24 was cloned into the multiple cloning site of the manipulated Sabin cDNA. A recombinant progeny virus was produced from HeLa cells when it was transfected with the RNA synthesized from the p24-Sabin chimeric cDNA. The recombinant progeny virus expresses substantial amounts of the HIV-1 p24 protein, which was clearly detected in the infected cell lysates and culture supernatants in Western blot experiments with rabbit anti-p24 serum and AIDS patients' sera. Differing from the Mahoney strain, the recombinant Sabin 1 poliovirus maintained the foreign gene stably during the subsequent passages. Replication capacity was about 1 to 1.5 log lower than that of the wild-type Sabin 1. Other physicochemical stability characteristics of the recombinant virus were similar to that of the wild-type Sabin 1. These results suggest that the manipulated Sabin 1 poliovirus can be used as a live viral vaccine vector for the development of mucosal vaccines.

• IMMUNE NETWORK
• /
• v.12 no.1
• /
• pp.8-17
• /
• 2012

Background: Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract diseases in infancy and early childhood. Despite its importance as a pathogen, there is no licensed vaccine against RSV yet. The attachment glycoprotein (G) of RSV is a potentially important target for protective antiviral immune responses. Recombinant baculovirus has been recently emerged as a new vaccine vector, since it has intrinsic immunostimulatory properties and good bio-safety profile. Methods: We have constructed a recombinant baculovirus-based RSV vaccine, Bac-RSV/G, displaying G glycoprotein, and evaluated immunogenicity and protective efficacy by intranasal immunization of BALB/c mice with Bac-RSV/G. Results: Bac-RSV/G efficiently provides protective immunity against RSV challenge. Strong serum IgG and mucosal IgA responses were induced by intranasal immunization with Bac-RSV/G. In addition to humoral immunity, G-specific Th17- as well as Th1-type T-cell responses were detected in the lungs of Bac-RSV/G-immune mice upon RSV challenge. Neither lung eosinophilia nor vaccine-induced weight loss was observed upon Bac-RSV/G immunization and subsequent RSV infection. Conclusion: Our data demonstrate that intranasal administration of baculovirus-based Bac-RSV/G vaccine is efficient for the induction of protection against RSV and represents a promising prophylactic vaccination regimen.

• The Journal of the Korean Society for Microbiology
• /
• v.21 no.2
• /
• pp.243-249
• /
• 1986

A study of the immunogenicity and reactogenicity of two doses of lot H(10, 20 mcg), two doses of lot L (20, 40 mcg) of the Smith Kline-RIT recombinant DNA yeast-derived hepatitis B vaccine and a 20-mcg dose of the Merck Sharp and Dohme plasma-derived hepatitis B vaccine was conducted in young adults under randomized, double-blind conditions. Immunization was carried out according to a 0-, 1-, and 6-month vaccination schedule. Results indicated that the yeast-derived hepatitis B vaccine was well tolerated and immunogenic. Reactogenicity to both yeast- and plasma-derived vaccines was mild in severity and low in incidence with no significant differences appearing between the study groups. One month after the third dose, the yeast-derived vaccines induced a high degree of soroconversion ranging between 95.0% and 100%. The response was not lot or dose-dependent. The administration of the plasma-derived vaccine resulted in anti-HBs geometric mean titres statistically signifirantly higher than those elicited by the different yeast-derived hepatitis B vaccines one month after the third dose of vaccine but the difference was not large enough to be of great clinical significance.

• IMMUNE NETWORK
• /
• v.5 no.2
• /
• pp.89-98
• /
• 2005

Background: DNA vaccination represents an anticipated approach for the control of numerous infectious diseases. Used alone, however, DNA vaccine is weak immunogen inferior to viral vectors. In recent, heterologous prime-boost vaccination leads DNA vaccines to practical reality. Methods: We assessed prime-boost immunization strategies with a DNA vaccine (minigene, $gB_{498-505}$ DNA) and recombinant vaccinia virus $(vvgB_{498-505})$ expressing epitope $gB_{498-505}$ (SSIEF ARL) of CD8+ T cells specific for glycoprotein B (gB) of herpes simplex virus (HSV). Animals were immunized primarily with $gB_{498-505}$ epitope-expressing DNA vaccine/recombinant vaccinia virus and boosted with alternative vaccine type expressing entire Ag. Results: In prime-boost protocols using vvgBw (recombinant vaccinia virus expressing entire Ag) and $vvgB_{498-505}$, CD8+ T cell-mediated immunity was induced maximally at both acute and memory stages if primed with vvgBw and boosted with $vvgB_{498-505}$ as evaluated by CTL activity, intracellular IFN-staining, and MHC class I tetramer staining. Similarly $gB_{498-505}$ DNA prime-gBw DNA (DNA vaccine expressing entire Ag) boost immunization elicited the strongest CD8+ T cell responses in protocols based on DNA vaccine. However, the level of CD8+ T cell-mediated immunity induced with prime-boost vaccination using DNA vaccine expressing epitope or entire Ag was inferior to those based on vvgBw and $vvgB_{498-505}$. Of particular interest CD8+ T cell-mediated immunity was optimally induced when $vvgB_{498-505}$ was used to prime and gB DNA was used as alternative boost. Especially CD7+ T cell responses induced by such protocol was longer lasted than other protocols. Conclusion: These facts direct to search for the effective strategy to induce optimal CD8+ T cell-mediated immunity against cancer and viral infection.

• IMMUNE NETWORK
• /
• v.13 no.6
• /
• pp.275-282
• /
• 2013

Influenza virus is one of the major sources of respiratory tract infection. Due to antigenic drift in surface glycoproteins the virus causes annual epidemics with severe morbidity and mortality. Although hemagglutinin (HA) is one of the highly variable surface glycoproteins of the influenza virus, it remains the most attractive target for vaccine development against seasonal influenza infection because antibodies generated against HA provide virus neutralization and subsequent protection against the virus infection. Combination of recombinant adenovirus (rAd) vector-based vaccine and mucosal administration is a promising regimen for safe and effective vaccination against influenza. In this study, we constructed rAd encoding the globular head region of HA from A/Puerto Rico/8/34 virus as vaccine candidate. The rAd vaccine was engineered to express high level of the protein in secreted form. Intranasal or sublingual immunization of mice with the rAd-based vaccine candidates induced significant levels of sustained HA-specific mucosal IgA and IgG. When challenged with lethal dose of homologous virus, the vaccinated mice were completely protected from the infection. The results demonstrate that intranasal or sublingual vaccination with HA-encoding rAd elicits protective immunity against infection with homologous influenza virus. This finding underlines the potential of our recombinant adenovirus-based influenza vaccine candidate for both efficacy and rapid production.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.2
• /
• pp.280-287
• /
• 2015

Current influenza vaccines are produced in embryonated chicken eggs. However, egg-based vaccines have various problems. To address these problems, recombinant protein vaccines have been developed as new vaccine candidates. Unfortunately, recombinant proteins frequently encounter aggregation and low stability during their biogenesis. It has been previously demonstrated that recombinantly expressed proteins can be greatly stabilized with high solubility by fusing stabilizing peptide (SP) derived from the C-terminal acidic tail of human synuclein (ATS). To investigate whether SP fusion proteins can induce protective immunity in mice, we produced influenza HA and SP fusion protein using a baculovirus expression system. In in vitro tests, SP-fused recombinant HA1 (SP-rHA1) was shown to be more stable than recombinant HA1 (rHA1). Mice were immunized intramuscularly with baculovirus-expressed rHA1 protein or SP-rHA1 protein ($2{\mu}g/mouse$) formulated with aluminum hydroxide. Antibody responses were determined by ELISA and hemagglutination inhibition assay. We observed that SP-rHA1 immunization elicited HA-specific antibody responses that were comparable to rHA1 immunization. These results indicate that fusion of SP to rHA1 does not negatively affect the immunogenicity of the vaccine candidate. Therefore, it is possible to apply SP fusion technology to develop stable recombinant protein vaccines with high solubility.